@Hikman... the last 2 times of the league where disqualified in the begining of the season because they were a part of fixing games fraud so they fell to the 2nd category. Now the teams that have 10 games played only is because they took the spot for the other two teams that got disqualified. The negative part is because of the second penalty they got as well as being disqualified which is start the season with less points than the rest of the teams.
I hope i helped a bit with yout question, though know that greek football is sadly overcomplicated and quiet corrupt.